In studies the incidence of respiratory symptoms is usually indicated as a single figure - and rhinitis, dyspnoea and asthmatic symptoms have not been defined separately.
In the follow-up study by Høst 1,749 children were monitored and the prevalence of respiratory symptoms in food challenge testing was less than 10 %. In the study by Schrander, 4 % of children developed rhinitis, 19 % a cough and 12 % wheezing , whereas in the Finnish study cohort of Saarinen 36 % manifested respiratory symptoms during challenge testing .
Sampson et al. carried out a prospective study on a cohort of 320 children and adolescents extending back over 11 years, whose presenting symptom was atopic eczema . The cohort population was highly select with, for example, the median IgE concentration being 3,400 IU/l. Forty-five per cent had asthma in addition to atopic eczema. The age distribution was weighted towards the pre-school age, the median age being 4.4 years. A food challenge was carried out in a total of 205 children (monitored for immediate reactions) and 121 (59 %) experienced respiratory reactions; 17 % developed nasal, laryngeal or pulmonary symptoms.